i noticed that the size of my /usr/portage/distfiles is getting quite hefty (461MB) after less than a week of using gentoo... (and i must say this distro rocks -- i just switched over from redhat)

my question is if gentoo manages and maintains this folder automagically? or do i have to keep an eye on it and delete files when it gets too big? and if that's the case, is it safe to just "rm *" in this directory, or is there a "portage way" to do this?

I would probably just add a script to /etc/cron.weekly/ to automatically clear the distfiles (maybe even check the creation date and delete after a certain period of time). That way, in case you do need the package again you can save some bandwidth and still use your disk space prudently.